<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .color{
            width: 100px;
            height: 100px;
            border-radius: 50%;
            -moz-border-radius: 50%;
            -webkit-border-radius: 50%;
            position:absolute;
        }
    </style>
    <script>
        var js = 0;
        function f() {
            if (js<101){
                js+=1;
                var ys ='#' + Math.floor( Math.random() * 0xffffff ).toString(16);
                x = Math.floor(Math.random()*(82-1)+1);
                y = Math.floor(Math.random()*(39-1)+1);
                var xq = "<div class='color' style='background-color: "+ys+";margin-top: "+y+"% ;margin-left: "+x+"%'></div>";
                document.getElementById('a').innerHTML+=xq;
            }
        }
    </script>
</head>
<body id="a" onload="setInterval('f()',100)">

</body>
</html>